WO2022253098A1 - 激光扫描显微测量装置及其方法 - Google Patents

激光扫描显微测量装置及其方法 Download PDF

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WO2022253098A1
WO2022253098A1 PCT/CN2022/095230 CN2022095230W WO2022253098A1 WO 2022253098 A1 WO2022253098 A1 WO 2022253098A1 CN 2022095230 W CN2022095230 W CN 2022095230W WO 2022253098 A1 WO2022253098 A1 WO 2022253098A1
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laser
light intensity
objective lens
detection module
scanning
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PCT/CN2022/095230
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English (en)
French (fr)
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赵裕兴
王承伟
徐海宾
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苏州德龙激光股份有限公司
江阴德力激光设备有限公司
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Publication of WO2022253098A1 publication Critical patent/WO2022253098A1/zh

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B21/00—Microscopes
    • G02B21/0004—Microscopes specially adapted for specific applications
    • G02B21/002—Scanning microscopes
    • G02B21/0024—Confocal scanning microscopes (CSOMs) or confocal "macroscopes"; Accessories which are not restricted to use with CSOMs, e.g. sample holders
    • G02B21/0036—Scanning details, e.g. scanning stages
    • G02B21/0048—Scanning details, e.g. scanning stages scanning mirrors, e.g. rotating or galvanomirrors, MEMS mirrors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B21/00—Microscopes
    • G02B21/0004—Microscopes specially adapted for specific applications
    • G02B21/002—Scanning microscopes
    • G02B21/0024—Confocal scanning microscopes (CSOMs) or confocal "macroscopes"; Accessories which are not restricted to use with CSOMs, e.g. sample holders
    • G02B21/0032—Optical details of illumination, e.g. light-sources, pinholes, beam splitters, slits, fibers
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B21/00—Microscopes
    • G02B21/0004—Microscopes specially adapted for specific applications
    • G02B21/002—Scanning microscopes
    • G02B21/0024—Confocal scanning microscopes (CSOMs) or confocal "macroscopes"; Accessories which are not restricted to use with CSOMs, e.g. sample holders
    • G02B21/008—Details of detection or image processing, including general computer control
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B21/00—Microscopes
    • G02B21/06—Means for illuminating specimens
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B21/00—Microscopes
    • G02B21/36—Microscopes arranged for photographic purposes or projection purposes or digital imaging or video purposes including associated control and data processing arrangements
    • G02B21/362—Mechanical details, e.g. mountings for the camera or image sensor, housings

Definitions

  • the invention relates to a laser scanning microscopic measuring device and a method thereof.
  • the optical components of the laser scanning confocal microscope include photomultiplier tubes and detection pinholes, lasers and light source pinholes.
  • the detection pinhole is small, which is easy to cause diffraction.
  • the image points of different object points of the sample on the detection surface of the photomultiplier tube have deviations, but the position of the detection pinhole is fixed, so the object point on the axis is different from the object point on the side axis. point deviation.
  • This application adopts the high frame rate area array camera developed rapidly in recent years, combined with the high-gain microchannel plate imaging detector to form a detection module, which replaces the photomultiplier tube with high sensitivity and fast response time;
  • a CCD element is used as a virtual pinhole to replace the detection pinhole.
  • the light intensity of the CCD element with the largest light intensity on each frame of the image is used to replace the light intensity detected by the photomultiplier tube after the pinhole, avoiding the paraxial and on-axis Point deviation, diffraction is avoided by canceling the detection pinhole.
  • the light spot after the light source pinhole is small, the energy utilization rate is low, and the light source pinhole is small and easy to cause diffraction; the beam expander is used to replace the light source pinhole, no light source pinhole diffraction can be avoided, and the energy utilization rate of the laser is high, and the focused spot size after the objective lens is reduced , to improve the lateral precision, the highest precision after Gaussian light focusing is 0.64 ⁇ /NA, which is better than the precision of ordinary optical microscope 1.22 ⁇ /NA.
  • the accuracy of the improved light source is comparable to the laser scanning confocal lateral resolution of 0.56 ⁇ /NA in the literature (Handbook of Image and Video Processing, Chapter 10, Section 9, Confocal microscope, page 1293).
  • the purpose of the present invention is to overcome the deficiencies in the prior art, and provide a laser scanning microscopic measuring device and its method.
  • the laser scanning microscopic measurement device is characterized by: including a laser, a half mirror, a vibrating mirror, a scanning objective lens, a three-dimensional displacement stage and a detection module, a half mirror is arranged on the output optical path of the laser, and the reflected light of the half mirror
  • the galvanometer and scanning objective lens are arranged in sequence on the road, and the detection module is arranged on the transmitted light path; the laser emits laser light, which is incident into the galvanometer through a half mirror, and the galvanometer controls the two-dimensional deflection of the laser.
  • the scanning objective lens After passing through the scanning objective lens, it focuses on the three-dimensional translation stage
  • the laser light is reflected after incident on the sample, returns to the scanning objective lens and galvanometer, and then enters the detection module after passing through the half mirror.
  • the three-dimensional translation platform includes a two-dimensional translation platform for two-dimensional movement of the X-axis and Y-axis, and a piezoelectric ceramic Z-axis connected to it for the up-and-down movement of the Z-axis Unit; the piezoelectric ceramic Z-axis unit moves the sample along the Z-axis.
  • the galvanometer controls the laser to scan the X-Y surface of the sample, and the detection module acquires images under different X-Y-Z coordinates, and single or multiple CCD elements
  • the detection module acquires images under different X-Y-Z coordinates, and single or multiple CCD elements
  • the light intensity of the virtual pinhole area with the largest light intensity in each image is obtained, and the light intensity values at different X-Y-Z coordinates are obtained, and the Z coordinate corresponding to the maximum light intensity at any X-Y coordinate is obtained, that is, the X-Y plane is obtained.
  • Depth distribution measuring the surface topography information of scratches and roughness.
  • the above-mentioned laser scanning microscopic measurement device wherein the laser is installed on the laser installation frame, the laser installation frame is fixed on the vertical screw, the vertical screw is installed on the first adapter plate, and the beam expander Installed on the first adapter plate through the adapter ring, the vertical screw is fixed on the second adapter plate, the second adapter plate is fixed on the cage orthogonal steering plate, and the cage orthogonal steering plate is installed on the horizontal screw
  • the half mirror is installed on the horizontal screw, one end of the horizontal screw is screwed with the vibrating mirror, the scanning objective lens is screwed with the vibrating mirror, the other end of the horizontal screw is installed with a third adapter plate, and the detection module is fixed on the Three adapter boards.
  • the detection module includes microchannel plate imaging detectors arranged in sequence for laser amplification, and the signals used to amplify the microchannel plate imaging detectors have no offset Fiber Optic Plates for High Frame Rate Area Scan Cameras and High Frame Rate Area Scan Cameras.
  • the above-mentioned laser scanning microscopic measurement device wherein, the high frame rate area array camera is fixed on the camera frame, the camera frame is fixed on the cage plate adapter through a screw, and the cage plate adapter is provided with a fiber optic plate, microchannel plate imaging detector, first retaining ring, protective lens, chamber of the second retaining ring, the fiber optic plate is located between the high frame rate area array camera and the microchannel plate imaging detector and is close to each other, the microchannel
  • the plate imaging detector is fixed by a first snap ring, a protective lens is placed in front of the first snap ring, and the protective lens is fixed by a second snap ring.
  • the high frame rate area array camera is an area array camera with a MHz frame rate
  • the microchannel plate imaging detector is a microchannel plate imaging detector with a signal amplification of 10 6 to 10 7 times device.
  • the laser is a laser capable of outputting a Gaussian distribution and a wavelength of 350-650 nm.
  • a beam expander is arranged on the output optical path of the laser.
  • the laser emits laser light, which is incident on the vibrating mirror through the half mirror, and the vibrating mirror controls the two-dimensional deflection of the laser. After the sample is reflected, the original path returns to the scanning objective lens and the vibrating mirror, and then enters the detection module after passing through the half mirror;
  • the galvanometer controls the laser to scan the X-Y surface of the sample, and the detection module acquires images in different X-Y-Z coordinates.
  • Single or multiple CCD elements are used as virtual pinholes to obtain each image.
  • the light intensity of the virtual pinhole area with the largest light intensity in the image can be obtained from the light intensity values under different X-Y-Z coordinates, and the Z coordinate corresponding to the maximum light intensity under any X-Y coordinate can be obtained, that is, the depth distribution of the X-Y plane can be obtained, and scratches, Surface topography information of roughness.
  • the laser outputs Gaussian distributed laser light, and the beam waist radius w 0 after passing through the vibrating mirror and scanning objective lens is expressed as:
  • ⁇ and w 1 respectively represent the wavelength and the incident spot size in front of the scanning objective lens;
  • the Rayleigh distance z 0 ⁇ w 0 2 / ⁇ ;
  • the waist spot radius w z at the distance z is expressed as follows:
  • the focal length of the scanning objective lens is f, and an image distance of 200mm is adopted, which is much larger than f , using the Gaussian imaging formula, the object distance is approximately equal to f;
  • the size of the CCD element of the high frame rate area array camera is S, x and y represent the coordinates on the camera surface; only the z axis is moved, the power measured at the image side is proportional to the laser power at the object side, and the total power at the image side is P 0 ;
  • the coordinate of the object space is z
  • the peak light intensity is I z
  • the power PS (z) of the spot center incident on the camera is expressed as:
  • the power P S (z) detected on the camera is always equal to the total power P 0 on the image side, regardless of the coordinate z; when single or multiple camera CCD elements are used, P S (z ) varies with the z-axis, when the beam waist is on the sample surface, w z is the smallest, PS (z) is the largest, and the height information of this point is detected.
  • the present invention has significant advantages and beneficial effects, which are embodied in the following aspects:
  • the present invention uses single or multiple CCD element points of an area array camera as virtual pinholes to avoid errors caused by edge diffraction of pinholes.
  • 2A scanning galvanometer is used to avoid measurement errors caused by sample shaking when the platform moves;
  • a detection module is composed of a high frame rate area array camera combined with a microchannel plate imaging detector to improve the measurement accuracy of the galvanometer scanning; each frame of image is adopted
  • the light intensity of the single or multiple CCD elements with the largest light intensity on the surface is used as the light intensity corresponding to the corresponding object point;
  • the virtual pinhole formed by the single or multiple CCD elements changes with the position of the object point, with a virtual pinhole
  • the light intensity measured by the detector of the hole is always the light intensity in the central area of the beam waist of the Gaussian beam;
  • the present invention uses a beam expander to replace the pinhole of the light source, avoiding diffraction without the pinhole of the light source, and the energy utilization rate of the laser is high.
  • the pinhole of the light source is small, and the light behind the pinhole is approximately evenly distributed. At different longitudinal positions, the spot size in front of the detection module changes but the light intensity is uniform.
  • the relative light intensity after the detection pinhole is equal to the area of the detection pinhole and the spot area Ratio; Gaussian distributed laser, under different longitudinal positions, the spot size before the detection module changes and the light intensity is weak at the center of the spot, and the relative light intensity after the virtual pinhole detection is equal to the integral of the light intensity in the pinhole area divided by The light intensity integral within the spot area; under the same pinhole area, the light intensity ratio after the virtual detection pinhole is greater than the light intensity ratio after the actual pinhole, so the signal strength and signal-to-noise ratio of the virtual pinhole detection module are higher.
  • the microchannel plate imaging detector, fiber optic plate and high frame rate area array camera constitute a detection module, which can not only replace pinholes and photomultiplier tubes, but also have lower cost and better stability; the microchannel plate imaging detector will The optical signal is converted into an electrical signal, and the electrons are imaged on the fluorescent screen, and the fiber optic plate transmits the image on the fluorescent screen to the camera; the image transmitted by the fiber optic plate has little distortion and no vignetting.
  • Fig. 1 the structural representation of device of the present invention
  • FIG. 1 Schematic diagram of the structure of the detection module
  • Fig. 2b A-A sectional schematic diagram of Fig. 2a;
  • Fig. 3 The present invention measures the surface topography photo of scratched glass
  • Figure 4 The relationship between normalized laser power and relative axial position (axial position divided by Rayleigh distance z 0 ) under different virtual pinhole sizes, where: a—virtual pinhole size is equal to beam waist diameter multiplied by Magnification, b—the virtual pinhole size is equal to the beam waist diameter;
  • Figure 5 Normalized laser power versus axial position for scan lenses with different focal lengths.
  • the present invention adopts a high frame rate area array camera, combined with a high-gain microchannel plate imaging detector and a fiber optic plate to form a detection module, and uses a single or multiple CCD elements of the area array camera as virtual pinholes, such as using each frame of image
  • the light intensity of the CCD element with the largest light intensity on the top avoids the deviation of the paraxial and on-axis points, and the diffraction can be avoided after canceling the detection of the pinhole.
  • the light spot after the light source pinhole is small, the energy utilization rate is low, and the light source pinhole is small and easy to cause diffraction; the beam expander is used, no light source pinhole diffraction can be avoided, and the energy utilization rate of the laser is high, the size of the focused spot after the objective lens is reduced, and the lateral accuracy is improved.
  • the highest precision of Gaussian light after focusing is 0.64 ⁇ /NA, which is significantly better than the precision of 1.22 ⁇ /NA of ordinary optical microscopes.
  • the laser scanning microscopic measurement device is characterized in that: it includes a laser 201, a half mirror 205, a vibrating mirror 206, a scanning objective lens 207, a three-dimensional displacement stage 208 and a detection module 210, and the laser 201 is capable of outputting Gaussian distribution, 350-650nm wavelength laser, beam expander 212, half mirror 205 are arranged in sequence on the output optical path of laser 201, vibrating mirror 206 and scanning objective lens 207 are arranged in turn on the reflected light path of half mirror 205, the transmitted light
  • a detection module 210 is arranged on the road.
  • the three-dimensional translation stage 208 includes a two-dimensional translation stage for two-dimensional movement of the X-axis and the Y-axis and a piezoelectric ceramic Z-axis unit connected to it for the Z-axis to move up and down; the piezoelectric ceramic Z-axis unit moves the sample along the Z-axis , at each Z coordinate, the vibrating mirror 206 controls the laser to scan the X-Y surface of the sample, and the detection module 210 acquires images under different X-Y-Z coordinates, using single or multiple CCD elements as virtual pinholes to obtain the light in each image
  • the laser 201 is installed on the laser installation frame 200, the laser installation frame 200 is fixed on the vertical screw 202, the vertical screw 202 is installed on the first adapter plate 211, and the beam expander 212 is installed on the first adapter plate through the adapter ring.
  • the vertical screw 202 is fixed on the second adapter plate 203
  • the second adapter plate 203 is fixed on the cage-type orthogonal turning plate 204
  • the cage-type orthogonal turning plate 204 is installed on the transverse screw rod 213
  • the half mirror 205 is installed on the transverse screw rod 213, one end of the transverse screw rod 213 is screwed to the vibrating mirror 206, the scanning objective lens 207 is screwed to the vibrating mirror 206, and the other end of the transverse screw rod 213 is installed with a third adapter plate 209
  • the detection module 210 is fixed on the third adapter board 209 .
  • the detection module 210 includes a microchannel plate imaging detector 311 arranged in sequence for laser amplification, and is used to transmit the amplified signal of the microchannel plate imaging detector to the high frame rate surface without offset.
  • the fiber optic plate 312 of the array camera and the high frame rate area array camera 301, the high frame rate area array camera 301 is an area array camera with a MHz frame rate, and the microchannel plate imaging detector 311 is a micro The channel plate imaging detector;
  • the high frame rate area array camera 301 is fixed on the camera frame 303 by screws on the first threaded hole 310 and the second threaded hole 314, and the camera frame 303 is fixed on the camera frame 303 by the first screw 305, the second screw 306, and the third screw 307
  • the cage plate adapter 302 is provided with a chamber for accommodating a fiber optic plate 312, a microchannel plate imaging detector 311, a first snap ring 308, a protective lens 309, and a second snap ring
  • the laser 201 emits laser light, which is incident on the vibrating mirror 206 through the semi-reflective mirror 205.
  • the vibrating mirror 206 controls the two-dimensional deflection of the laser. After passing through the scanning objective lens 207, it focuses on the sample on the three-dimensional translation stage 208. Reflection, return to the scanning objective lens 207 and vibrating mirror 206 in the same way, and then enter the detection module 210 after passing through the half mirror 205; measure the 3D shape of the scratch, measure the roughness of the scratch area and its surroundings, and measure the roughness of each point in the area
  • the maximum height value R p of the area, the minimum height value R v of each point in the area, the peak and valley value of the scratch is equal to R p –R v ;
  • the galvanometer 206 controls the laser to scan the X-Y surface of the sample, and the detection module 210 acquires images at different X-Y-Z coordinates.
  • Single or multiple CCD elements are used as virtual pinholes to obtain The light intensity of the virtual pinhole area with the largest light intensity in each image can be obtained from the light intensity values under different X-Y-Z coordinates, and the Z coordinate corresponding to the maximum light intensity under any X-Y coordinate can be obtained, that is, the depth distribution of the X-Y plane can be obtained, and the stroke can be measured.
  • the laser 201 outputs Gaussian-distributed laser light, and the beam waist radius w0 after passing through the vibrating mirror 206 and the scanning objective lens 207 is expressed as:
  • ⁇ and w 1 respectively represent the wavelength and the incident spot size in front of the scanning objective lens;
  • the Rayleigh distance z 0 ⁇ w 0 2 / ⁇ ;
  • the waist spot radius w z at the distance z is expressed as follows:
  • the focal length of the scanning objective lens is f, and an image distance of 200mm is adopted, which is much larger than f , using the Gaussian imaging formula, the object distance is approximately equal to f;
  • the size of the CCD element of the high frame rate area array camera is S, x and y represent the coordinates on the camera surface; only the z axis is moved, the power measured at the image side is proportional to the laser power at the object side, and the total power at the image side is P 0 ;
  • the coordinate of the object space is z
  • the peak light intensity is I z
  • the power PS (z) of the spot center incident on the camera is expressed as:
  • the power P S (z) detected on the camera is always equal to the total power P 0 on the image side, regardless of the coordinate z; when single or multiple camera CCD elements are used, P S (z ) changes with the z-axis, when the beam waist is on the sample surface, w z is the smallest, PS (z) is the largest, and the height information of this point is detected; the detected power ratio P S (z)/P 0 varies with the virtual needle
  • the hole size S decreases, the virtual pinhole size S is equal to the beam waist diameter w z multiplied by the magnification M A , the power after the pinhole is equal to 98.2% of the total power; the virtual pinhole size drops to the beam waist diameter w z , the power ratio PS (z)/P 0 decreases, and the power ratio PS (z)/P 0 decreases with the increase of the magnification; when the magnification M A is equal to 10, the power ratio PS (z )/
  • a 405nm laser 201 with a maximum power of 200mW (Changchun New Industry Optoelectronics Technology Co., Ltd., model MDL-XS-405) emits a 1.2mm diameter laser beam, which passes through a beam expander 212 with a variable magnification of 2 to 5 times (Solebo, model BE -02-05-A) After the spot size is enlarged, it is reflected by the semi-reflective mirror 205 into the vibrating mirror 206, and the vibrating mirror 206 controls the two-dimensional deflection of the laser.
  • the vibrating mirror with sensor measurement is used to allow the vibrating mirror to work in a closed loop And can output the coordinates of the galvanometer.
  • the three-dimensional translation stage is composed of a two-dimensional translation stage and a piezoelectric ceramic Z-axis unit.
  • the two-dimensional translation stage (Solebo, model MLS203-1) realizes X
  • the two-dimensional movement of the axis and the Y axis, the piezoelectric ceramic Z-axis unit (Solebo, model MZS500-E) realizes the Z-axis up and down movement, the maximum stroke is 500 ⁇ m, and the resolution is 25nm; the laser is reflected after incident on the sample and returns to the scanning objective lens 207 and the vibrating mirror 206, after passing through the half mirror 205, enter the detection module 210.
  • the image square laser is amplified by the microchannel plate imaging detector 311 (dmphotonics, model microchannel plate-IFP 25/2), and the fiber optic plate 312 (SZPHOTON, model FOP-DSP) amplifies the signal of the microchannel plate imaging detector without bias Transfer to the high frame rate area array camera 301 (model ISIS, reference A 16 Mfps 165 kpixel backside-illuminated CCD, Evolution of High-Speed Image Sensors, A Backside-Illuminated Image Sensor with 200,000 Pixels Operating at 250,000 Frames per Second And An image sensor which captures 100 consecutive frames at 1000000 frames_s), high frame rate camera ISIS indicators are summarized as follows:
  • Wavelength range 350-650nm
  • the photosensitive chip size is 15.6mm ⁇ 19.7mm, and the photosensitive chip is packaged in part 301 with ceramics;
  • the incident light spot is smaller than the diameter of the entrance pupil of the scanning lens, for example, the entrance light spot is used for half of the entrance pupil diameter, allowing the incident light to be inclined by half.
  • the galvanometer rotates fast and avoids measurement errors caused by sample shaking during platform movement.
  • the platform has a large inertia, and the acceleration and deceleration time is about 100ms.
  • the light acceleration and deceleration time of the galvanometer is short, and the scanning delay is usually less than 1ms.
  • the galvanometer scanning method is used to reduce the acceleration and deceleration time.
  • Example 2 Measurement of peak and valley values of scratches by laser scanning microscopy.
  • Piezoelectric ceramics move Z-axis displacement 20 ⁇ m, step size 0.25 ⁇ m.
  • a scanning objective lens with a focal length of 4 mm is used to scan the surface of the glass sample, with a single scanning format of 282.6 ⁇ m ⁇ 210 ⁇ m, and the scanning angles in the X-Y directions are 4.0° and 3.0°, respectively.
  • the photo of the measured surface topography of scratches is shown in Figure 3.
  • the maximum height value Rp of each point in this area is 2.65 ⁇ m
  • the minimum height value Rv of each point in this area is -2.72 ⁇ m
  • the virtual pinhole size corresponding to curve a and curve b is the magnification of the scanning objective lens multiplied by the beam waist size and the beam waist size respectively.
  • the half-height width of curve a is larger than curve b, so the smaller the virtual pinhole size, the better the longitudinal Z-axis accuracy. high.
  • the smaller the size the lower the intensity, which requires a high magnification and sufficient sensitivity of the detection module.
  • it can also be achieved by reducing the focal length of the scanning objective lens.
  • the relationship between the normalized power and the axial position calculated according to the PS (z) formula is shown in Figure 5.
  • the galvanometer is fixed at an XY coordinate point, and the sample is moved through the piezoelectric ceramic to measure the laser power behind the virtual pinhole at different Z coordinates.
  • the laser emits a 1.2mm spot, and the spot size becomes 3.6mm after passing through a 3x beam expander.
  • the magnification of the scanning objective lens is increased from 50 times to 100 times, the focal length is reduced from 4mm to 2mm, and the full width at half maximum is reduced from 1.3 ⁇ m to 0.31 ⁇ m.
  • the present invention uses single or multiple CCD element points of the area array camera as virtual pinholes to avoid errors caused by edge diffraction of the pinholes.
  • the scanning galvanometer is used to avoid the measurement error caused by the sample shaking when the platform moves;
  • the detection module is composed of a high frame rate area array camera combined with a microchannel plate imaging detector to improve the measurement accuracy when the galvanometer scans.
  • the light intensity of the single or multiple CCD elements with the largest light intensity on each frame of image is used as the light intensity corresponding to the corresponding object point;
  • the virtual pinhole formed by single or multiple CCD elements changes with the position of the object point.
  • the light intensity measured by a detector with a virtual pinhole is always the light intensity in the central region of the beam waist of a Gaussian beam.
  • the invention adopts a beam expander to replace the pinhole of the light source, avoids diffraction without the pinhole of the light source, and has high energy utilization rate of the laser.
  • the pinhole of the light source is small, and the light behind the pinhole is approximately evenly distributed. At different longitudinal positions, the spot size in front of the detection module changes but the light intensity is uniform.
  • the relative light intensity after the detection pinhole is equal to the ratio of the area of the detection pinhole to the area of the spot ; Gaussian distributed laser, under different longitudinal positions, the size of the spot before the detection module changes and the light intensity is strong at the center of the spot and weak at the edge, and the relative light intensity after the virtual pinhole detection is equal to the integral of the light intensity in the pinhole area divided by the spot Light intensity integration within the area; under the same pinhole area, the light intensity ratio after the virtual pinhole detection is greater than the light intensity ratio after the actual pinhole, so the signal strength and signal-to-noise ratio of the virtual pinhole detection module are higher.
  • Microchannel plate imaging detector, fiber optic plate and high frame rate area array camera constitute a detection module, which can not only replace pinholes and photomultiplier tubes, but also have lower cost and better stability; microchannel plate imaging detector combines light The signal is converted into an electrical signal, and the electrons are imaged on the fluorescent screen, and the fiber optic plate transmits the image on the fluorescent screen to the camera; the image transmitted by the fiber optic plate has small distortion and no vignetting; compared with the lens, the image transmitted by the fiber optic plate is overall The offset is small; the fiber optic board has been used in the optical fingerprint module of the mobile phone, and the fingerprint image is accurately transmitted to the CMOS or CCD camera, so the cost of the fiber optic board is low.

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Abstract

一种激光扫描显微测量装置及方法，激光器（201）的输出光路上布置半反半透镜（205），半反半透镜（205）的反射光路上依次布置振镜（206）和扫描物镜（207），透射光路上布置检测模组（210）；激光器（201）发出激光，经半反半透镜（205）入射到振镜（206）中，振镜（206）控制激光二维偏转，经扫描物镜（207）后，聚焦于三维位移台（208）上的样品上，激光入射到样品后发生反射，返回扫描物镜（207）和振镜（206），再经半反半透镜（205）后进入检测模组（210）；检测模组（210）获取不同X‑Y‑Z坐标下的图像，以单个或多个CCD元件作为虚拟针孔，获取每幅图像中光强最大的虚拟针孔区域的光强，获得不同X‑Y‑Z坐标下的光强值，得到任意X‑Y坐标下最大光强对应的Z坐标，即得到X‑Y平面的深度分布，测量出划痕、粗糙度的表面形貌信息。

Description

激光扫描显微测量装置及其方法 技术领域
本发明涉及一种激光扫描显微测量装置及其方法。
背景技术
专著Handbook of Image and Video Processing(Second Edition)第10章第9节Confocal microscope第1293页、《激光扫描共聚焦显微镜技术》第4页、《激光扫描共聚焦显微术》第2页都公开了激光扫描共聚焦显微镜光路图；《激光扫描共聚焦显微镜技术》第4页总结所述，“近几十年来，光学显微镜的光学部件改变不大”；《激光扫描共聚焦显微术》第1章第5节各公司仪器性能简介，激光扫描共聚焦显微镜的光学部件都包括光电倍增管和检测针孔、激光器和光源针孔。为了提高纵向分辨率，检测针孔小，易引起衍射，样品的不同物点在光电倍增管检测面的像点有偏差，但检测针孔位置固定，因此轴上的物点与旁轴的物点存在偏差。
本申请采用近年来快速发展的高帧率面阵相机，结合高增益的微通道板成像探测器构成检测模组，替代高灵敏度、响应时间快的光电倍增管；并用面阵相机的单个或多个CCD元件作为虚拟针孔，替代探测针孔，比如用每帧图像上的光强最大的CCD元件的光强，替代针孔后的光电倍增管探测的光强，避免了旁轴和轴上点的偏差，取消探测针孔后衍射得以避免。光源针孔后光斑小，能量利用率低，光源针孔小易引起衍射；采用扩束镜替代掉光源针孔，没有光源针孔衍射得以避免，且激光器能量利用率高，缩小物镜后聚焦的光斑尺寸，提高横向精度，高斯光聚焦后的最高精 度0.64λ/NA，优于普通光学显微镜精度1.22λ/NA。改进后的光源的精度与文献(Handbook of Image and Video Processing第10章第9节Confocal microscope第1293页)中的激光扫描共聚焦横向分辨率0.56λ/NA相当。
发明内容
本发明的目的是克服现有技术存在的不足，提供一种激光扫描显微测量装置及其方法。
本发明的目的通过以下技术方案来实现：
激光扫描显微测量装置，特点是：包含激光器、半反半透镜、振镜、扫描物镜、三维位移台和检测模组，激光器的输出光路上布置半反半透镜，半反半透镜的反射光路上依次布置振镜和扫描物镜，透射光路上布置检测模组；激光器发出激光，经过半反半透镜入射到振镜中，振镜控制激光二维偏转，经过扫描物镜后，聚焦于三维位移台上的样品上，激光入射到样品后发生反射，返回扫描物镜和振镜，再经过半反半透镜后进入检测模组。
进一步地，上述的激光扫描显微测量装置，其中，三维位移台包含用于X轴与Y轴二维移动的二维位移台以及连接于其上用于Z轴上下移动的压电陶瓷Z轴单元；压电陶瓷Z轴单元沿Z轴移动样品，在每个Z坐标下，振镜控制激光扫描样品的X-Y面，由检测模组获取不同X-Y-Z坐标下的图像，以单个或多个CCD元件作为虚拟针孔，获取每幅图像中光强最大的虚拟针孔区域的光强，获得不同X-Y-Z坐标下的光强值，得到任意X-Y坐标下最大光强对应的Z坐标，即得到X-Y平面的深度分布，测量出划痕、粗糙度的表面形貌信息。
进一步地，上述的激光扫描显微测量装置，其中，所述激光器安装于激光器安装架上，激光器安装架固定于竖向螺杆上，竖向螺杆上安装在第一转接板上，扩束镜通过转接环安装于第一转接板上，竖向螺杆固定在第二转接板上，第二转接板固定在笼式正交转向板上，笼式正交转向板安装 在横向螺杆上，半反半透镜安装在横向螺杆上，横向螺杆的一端与振镜相旋接，扫描物镜与振镜相旋接，横向螺杆的另一端安装第三转接板，检测模组固定在第三转接板上。
进一步地，上述的激光扫描显微测量装置，其中，所述检测模组包含依次设置的用于激光放大的微通道板成像探测器、用于将微通道板成像探测器放大的信号无偏移传送给高帧率面阵相机的光纤光学板以及高帧率面阵相机。
进一步地，上述的激光扫描显微测量装置，其中，高帧率面阵相机固定在相机架上，相机架通过螺杆固定在笼板转接件上，笼板转接件设有用于容纳光纤光学板、微通道板成像探测器、第一卡环、保护镜片、第二卡环的腔室，光纤光学板位于高帧率面阵相机与微通道板成像探测器之间并紧靠，微通道板成像探测器由第一卡环固定，第一卡环前放置有保护镜片，保护镜片由第二卡环固定。
进一步地，上述的激光扫描显微测量装置，其中，高帧率面阵相机为MHz帧率的面阵相机，微通道板成像探测器为信号放大10 6～10 7倍的微通道板成像探测器。
进一步地，上述的激光扫描显微测量装置，其中，激光器为可输出高斯分布、350～650nm波长的激光器。
进一步地，上述的激光扫描显微测量装置，其中，激光器的输出光路上布置扩束镜。
本发明激光扫描显微测量方法，激光器发出激光，经过半反半透镜入射到振镜中，振镜控制激光二维偏转，经过扫描物镜后，聚焦于三维位移台上的样品上，激光入射到样品后发生反射，原路返回扫描物镜和振镜，再经过半反半透镜后进入检测模组；
沿Z轴移动样品，在每个Z坐标下，振镜控制激光扫描样品的X-Y面，由检测模组获取不同X-Y-Z坐标下的图像，以单个或多个CCD元件作为虚拟针孔，获取每幅图像中光强最大的虚拟针孔区域的光强，获得不同X-Y-Z坐标下的光强值，得到任意X-Y坐标下最大光强对应的Z坐标，即得到X-Y平面的深度分布，测量出划痕、粗糙度的表面形貌信息。
更进一步地，上述的激光扫描显微测量方方达，激光器输出高斯分布的激光，经过振镜和扫描物镜后的束腰半径w 0表示为：
Figure PCTCN2022095230-appb-000001
式中λ和w 1分别表示波长和扫描物镜前的入射光斑尺寸；瑞利距离z 0＝πw 0 2/λ；距离z处的腰斑半径w z表示如下：
Figure PCTCN2022095230-appb-000002
式中z＝-z c表示束腰的坐标位置，坐标z轴沿着激光传播方向，束腰处光斑尺寸w z最小；扫描物镜的焦距为f，采用200mm的像距，像距远大于f，利用高斯成像公式，物距约等于f；物镜的放大倍数为M A＝200/f，检测模组的高帧率面阵相机上的光斑尺寸近似为M Aw z；
高帧率面阵相机CCD元件尺寸为S，x和y表示相机面上的坐标；只移动z轴，像方测到的功率与物方激光功率成正比，像方总功率为P 0；当物方坐标为z时，峰值光强为I z，入射到相机上的光斑中心的功率P S(z)表示为：
Figure PCTCN2022095230-appb-000003
当虚拟针孔尺寸S足够大时，相机上探测到的功率P S(z)始终等于像方 总功率P 0，与坐标z无关；当采用单个或多个相机CCD元件时，P S(z)随z轴变化，当束腰处于样品表面时，w z最小，P S(z)最大，探测出该点的高度信息。
本发明与现有技术相比具有显著的优点和有益效果，具体体现在以下方面：
①本发明采用面阵相机的单个或多个CCD元件点作为虚拟针孔，避免针孔边沿衍射引起的误差。
②采用扫描振镜，避免平台移动时样品晃动引起的测量误差；采用高帧率的面阵相机结合微通道板成像探测器构成检测模组，改善振镜扫描时的测量精度；采用每帧图像上的光强最大的单个或者多个CCD元件的光强，作为对应物点对应的光强；单个或者多个CCD元件构成的虚拟针孔，随着物点的位置的变化而变化，带虚拟针孔的探测器测量到的光强始终是高斯光束的束腰中心区域光强；
③本发明采用扩束镜替代掉光源针孔，没有光源针孔衍射得以避免，且激光器能量利用率高。
④光源针孔小，针孔后的光近似均匀分布，不同纵向位置下，探测模组前的光斑尺寸变化但光强均匀，探测针孔后的相对光强等于探测针孔面积与光斑面积的比例；高斯分布的激光，不同纵向位置下，探测模组前的光斑尺寸变化且光强在光斑中心强边缘弱，虚拟探测针孔后的相对光强等于针孔面积内的光强积分除以光斑面积内的光强积分；相同针孔面积下，虚拟探测针孔后的光强比大于实际针孔后的光强比，因此虚拟针孔探测模组的信号强度和信噪比更高。
⑤微通道板成像探测器、光纤光学板和高帧率面阵相机构成检测模组，不仅可以替代针孔和光电倍增管，而且成本更低、稳定性更好；微通道板成像探测器将光信号转化为电信号，电子在荧光屏上成像，光纤光学 板将荧光屏上的成像传递到相机上；光纤光学板传递的像畸变小且无渐晕。
本发明的其他特征和优点将在随后的说明书阐述，并且，部分地从说明书中变得显而易见，或者通过实施本发明具体实施方式了解。本发明的目的和其他优点可通过在所写的说明书、权利要求书、以及附图中所特别指出的结构来实现和获得。
附图说明
为了更清楚地说明本发明实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本发明的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1：本发明装置的结构示意图；
图2a：检测模组的结构示意图；
图2b：图2a的A-A剖视示意图；
图3：本发明测量有划痕的玻璃的表面形貌照片；
图4：不同虚拟针孔尺寸下，归一化激光功率与相对轴向位置(轴向位置除以瑞利距离z 0)的关系图，其中：a—虚拟针孔尺寸等于束腰直径乘以放大率，b—虚拟针孔尺寸等于束腰直径；
图5：不同焦距的扫描透镜下，归一化激光功率与轴向位置的关系图。
具体实施方式
下面将结合本发明实施例中附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。通常在此处附图中描述和示出的本发明实施例的组 件可以以各种不同的配置来布置和设计。因此，以下对在附图中提供的本发明的实施例的详细描述并非旨在限制要求保护的本发明的范围，而是仅仅表示本发明的选定实施例。基于本发明的实施例，本领域技术人员在没有做出创造性劳动的前提下所获得的所有其他实施例，都属于本发明保护的范围。
应注意到：相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步定义和解释。同时，在本发明的描述中，方位术语和次序术语等仅用于区分描述，而不能理解为指示或暗示相对重要性。
本发明采用高帧率面阵相机，结合高增益的微通道板成像探测器以及光纤光学板构成检测模组，并用面阵相机的单个或多个CCD元件作为虚拟针孔，比如用每帧图像上的光强最大的CCD元件的光强，避免旁轴和轴上点的偏差，取消探测针孔后衍射得以避免。光源针孔后光斑小，能量利用率低，光源针孔小易引起衍射；采用扩束镜，没有光源针孔衍射得以避免，且激光器能量利用率高，缩小物镜后聚焦的光斑尺寸，提高横向精度，高斯光聚焦后的最高精度0.64λ/NA，显著优于普通光学显微镜精度1.22λ/NA。
如图1所示，激光扫描显微测量装置，其特征在于：包含激光器201、半反半透镜205、振镜206、扫描物镜207、三维位移台208和检测模组210，激光器201为可输出高斯分布、350～650nm波长的激光器，激光器201的输出光路上依次布置扩束镜212、半反半透镜205，半反半透镜205的反射光路上依次布置振镜206和扫描物镜207，透射光路上布置检测模组210。
三维位移台208包含用于X轴与Y轴二维移动的二维位移台以及连接于其上用于Z轴上下移动的压电陶瓷Z轴单元；压电陶瓷Z轴单元沿Z轴移动样品，在每个Z坐标下，振镜206控制激光扫描样品的X-Y面，由 检测模组210获取不同X-Y-Z坐标下的图像，以单个或多个CCD元件作为虚拟针孔，获取每幅图像中光强最大的虚拟针孔区域的光强，获得不同X-Y-Z坐标下的光强值，得到任意X-Y坐标下最大光强对应的Z坐标，即得到X-Y平面的深度分布，测量出划痕、粗糙度的表面形貌信息。
激光器201安装于激光器安装架200上，激光器安装架200固定于竖向螺杆202上，竖向螺杆202上安装在第一转接板211上，扩束镜212通过转接环安装于第一转接板211上，竖向螺杆202固定在第二转接板203上，第二转接板203固定在笼式正交转向板204上，笼式正交转向板204安装在横向螺杆213上，半反半透镜205安装在横向螺杆213上，横向螺杆213的一端与振镜206相旋接，扫描物镜207与振镜206相旋接，横向螺杆213的另一端安装第三转接板209，检测模组210固定在第三转接板209上。
如图2a、2b所示，检测模组210包含依次设置的用于激光放大的微通道板成像探测器311、用于将微通道板成像探测器放大的信号无偏移传送给高帧率面阵相机的光纤光学板312以及高帧率面阵相机301，高帧率面阵相机301为MHz帧率的面阵相机，微通道板成像探测器311为信号放大10 6～10 7倍的微通道板成像探测器；高帧率面阵相机301通过螺纹孔一310和螺纹孔二314上的螺钉固定在相机架303上，相机架303通过螺杆一305、螺杆二306、螺杆三307固定在笼板转接件302上，笼板转接件302设有用于容纳光纤光学板312、微通道板成像探测器311、第一卡环308、保护镜片309、第二卡环304的腔室，零工作距离的光纤光学板312紧靠着高帧率面阵相机301和微通道板成像探测器311，微通道板成像探测器311由第一卡环308固定，第一卡环308前放置保护镜片309，保护镜片309前由第二卡环304固定。
激光器201发出激光，经过半反半透镜205入射到振镜206中，振镜206控制激光二维偏转，经过扫描物镜207后，聚焦于三维位移台208上 的样品上，激光入射到样品后发生反射，原路返回扫描物镜207和振镜206，再经过半反半透镜205后进入检测模组210；测量得到划痕的3D形貌，测得划痕区域及周边的粗糙度，区域各点的最大高度值R p，区域各点的最小高度值R v，划痕峰谷值等于R p–R v；
沿Z轴移动样品，在每个Z坐标下，振镜206控制激光扫描样品的X-Y面，由检测模组210获取不同X-Y-Z坐标下的图像，以单个或多个CCD元件作为虚拟针孔，获取每幅图像中光强最大的虚拟针孔区域的光强，获得不同X-Y-Z坐标下的光强值，得到任意X-Y坐标下最大光强对应的Z坐标，即得到X-Y平面的深度分布，测量出划痕、粗糙度的表面形貌信息；
激光器201输出高斯分布的激光，经过振镜206和扫描物镜207后的束腰半径w 0表示为：
Figure PCTCN2022095230-appb-000004
式中λ和w 1分别表示波长和扫描物镜前的入射光斑尺寸；瑞利距离z 0＝πw 0 2/λ；距离z处的腰斑半径w z表示如下：
Figure PCTCN2022095230-appb-000005
式中z＝-z c表示束腰的坐标位置，坐标z轴沿着激光传播方向，束腰处光斑尺寸w z最小；扫描物镜的焦距为f，采用200mm的像距，像距远大于f，利用高斯成像公式，物距约等于f；物镜的放大倍数为M A＝200/f，检测模组210的高帧率面阵相机上的光斑尺寸近似为M Aw z；
高帧率面阵相机CCD元件尺寸为S，x和y表示相机面上的坐标；只移动z轴，像方测到的功率与物方激光功率成正比，像方总功率为P 0；当物方坐标为z时，峰值光强为I z，入射到相机上的光斑中心的功率P S(z)表示为：
Figure PCTCN2022095230-appb-000006
当虚拟针孔尺寸S足够大时，相机上探测到的功率P S(z)始终等于像方总功率P 0，与坐标z无关；当采用单个或多个相机CCD元件时，P S(z)随z轴变化，当束腰处于样品表面时，w z最小，P S(z)最大，探测出该点的高度信息；探测到的功率比P S(z)/P 0随着虚拟针孔尺寸S的减小而减小，虚拟针孔尺寸S等于束腰直径w z乘以放大率M A时，针孔后功率等于总功率的98.2％；虚拟针孔尺寸下降到束腰直径w z时，功率比P S(z)/P 0下降，功率比P S(z)/P 0随着放大率的增大而降低；当放大率M A等于10时，功率比P S(z)/P 0下降到3.92％；当放大率等于20时，功率比P S(z)/P 0下降到0.995％。
激光扫描显微测量
实施例1
最大功率为200mW的405nm激光器201(长春新产业光电技术有限公司，型号MDL-XS-405)发出1.2mm直径激光，经过2～5倍可变倍率的扩束镜212(索雷博，型号BE-02-05-A)后光斑尺寸扩大，经过半反半透镜205反射到振镜206中，振镜206控制激光二维偏转，采用带传感测量的振镜，允许振镜反射镜闭环工作且能够输出振镜坐标。经过扫描物镜207后，聚焦在三维位移台208上的样品上，三维位移台由二维位移台和压电陶瓷Z轴单元构成，二维位移台(索雷博，型号MLS203-1)实现X轴与Y轴的二维移动，压电陶瓷Z轴单元(索雷博，型号MZS500-E)实现Z轴上下移动，最大行程500μm，分辨率25nm；激光入射到样品后发生反射，返回扫描物镜207和振镜206，透射过半 反半透镜205后进入检测模组210。
像方激光经过微通道板成像探测器311(dmphotonics，型号微通道板-IFP 25/2)放大，光纤光学板312(SZPHOTON，型号FOP-DSP)将微通道板成像探测器放大的信号无偏移地传递给高帧率面阵相机301(型号ISIS，参考文献A 16 Mfps 165 kpixel backside-illuminated CCD,Evolution of High-Speed Image Sensors,A Backside-Illuminated Image Sensor with 200,000 Pixels Operating at 250,000 Frames per Second和An image sensor which captures 100 consecutive frames at 1000000 frames_s)，高帧率相机ISIS指标汇总如下：
灰度范围，10bit；
波长范围，350-650nm；
CCD元件尺寸3.0×3.6μm；
感光芯片尺寸，15.6mm×19.7mm，感光芯片用陶瓷封装在部件301里；
帧率，最高可达16MHz。
激光扫描显微测量，二维振镜测试样品三维形貌等信息，入射光斑小于扫描透镜入瞳直径，比如入射光斑用到入瞳直径的一半，允许入射光倾斜一半。振镜转速快，且避免了平台移动过程中样品晃动引起的测量误差。平台惯性大，加减速时间约为100ms，振镜轻加减速时间短，扫描延迟通常小于1ms，采用振镜扫描方式，减少加减速时间。
实施例2：激光扫描显微测量划痕峰谷值。
压电陶瓷移动Z轴位移20μm，步长0.25μm。每个Z轴坐标下，采用焦距为4mm的扫描物镜扫描玻璃样品表面，单次扫描幅面282.6μm×210μm，X-Y两个方向的扫描角度分别为4.0°和3.0°。测量划痕表面形貌照片如图3所示，该区域各点的最大高度值Rp为2.65μm，该区域个点的最小高度值Rv为-2.72μm，划痕峰谷值等于Rp–Rv＝5.4μm。
实施例3
不同虚拟针孔尺寸下，根据P S(z)公式计算的归一化功率与轴向位置的关系如图4所示。曲线a和曲线b对应的虚拟针孔尺寸分别为扫描物镜放大倍数乘以束腰尺寸、束腰尺寸，曲线a的半高宽大于曲线b，因此虚拟针孔尺寸越小，纵向Z轴精度越高。但尺寸越小，强度越低，要求探测模组的放大倍率高、灵敏度足够。提高纵向精度，除了减小虚拟针孔尺寸，还可以通过减小扫描物镜焦距来实现。
实施例4
不同焦距扫描物镜下，根据P S(z)公式计算的归一化功率与轴向位置的关系如图5所示。振镜固定在一个X-Y坐标点，通过压电陶瓷移动样品，测量不同Z坐标下的虚拟针孔后的激光功率。激光器出射1.2mm光斑，经过3倍扩束镜后光斑尺寸变为3.6mm。扫描物镜倍数从50倍增大到100倍，焦距从4mm降低至2mm，半高宽从1.3μm降低到0.31μm。灰度10bit的面阵相机，分辨率为1/1024＝0.098％。50倍物镜，虚拟针孔尺寸等于单个CCD元件尺寸3.0μm×3.6μm时，当位置变化93nm，归一化功率下降到98.0％，2.0％的差别能够被面阵相机测试出来，因此纵向精度可以达到93nm。100倍物镜，虚拟针孔尺寸等于单个CCD元件尺寸3.0μm×3.6μm时，当位置变化23nm，归一化功率下降到98.0％，因此纵向精度可以达到23nm。
本发明采用面阵相机的单个或多个CCD元件点作为虚拟针孔，避免针孔边沿衍射引起的误差。
采用扫描振镜，避免平台移动时样品晃动引起的测量误差；采用高帧率的面阵相机结合微通道板成像探测器构成检测模组，改善振镜扫描时的测量精度。采用每帧图像上的光强最大的单个或者多个CCD元件的光强，作为对应物点对应的光强；单个或者多个CCD元件构成的虚拟针孔，随着物点的位置的变化而变化，带虚拟针孔的探测器测量到的光强始终是高 斯光束的束腰中心区域光强。
本发明采用扩束镜替代掉光源针孔，没有光源针孔衍射得以避免，且激光器能量利用率高。
光源针孔小，针孔后的光近似均匀分布，不同纵向位置下，探测模组前的光斑尺寸变化但光强均匀，探测针孔后的相对光强等于探测针孔面积与光斑面积的比例；高斯分布的激光，不同纵向位置下，探测模组前的光斑尺寸变化且光强在光斑中心强边缘弱，虚拟探测针孔后的相对光强等于针孔面积内的光强积分除以光斑面积内的光强积分；相同针孔面积下，虚拟探测针孔后的光强比大于实际针孔后的光强比，因此虚拟针孔探测模组的信号强度和信噪比更高。
微通道板成像探测器、光纤光学板和高帧率面阵相机构成检测模组，不仅可以替代针孔和光电倍增管，而且成本更低、稳定性更好；微通道板成像探测器将光信号转化为电信号，电子在荧光屏上成像，光纤光学板将荧光屏上的成像传递到相机上；光纤光学板传递的像畸变小且无渐晕；相比于透镜，光纤光学板传递的像整体偏移小；光纤光学板已应用于手机的光学指纹模组中，将指纹图像准确无误地传递给CMOS或CCD相机，因此光纤光学板成本低。
以上所述仅为本发明的优选实施例而已，并不用于限制本发明，对于本领域的技术人员来说，本发明可以有各种更改和变化。凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。应注意到：相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步定义和解释。
上述仅为本发明的具体实施方式，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内，可轻易 想到变化或替换，都应涵盖在本发明的保护范围之内。因此，本发明的保护范围应以权利要求所述的保护范围为准。
需要说明的是，在本文中，诸如第一和第二等之类的关系术语仅仅用来将一个实体或者操作与另一个实体或操作区分开来，而不一定要求或者暗示这些实体或操作之间存在任何这种实际的关系或者顺序。而且，术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法、物品或者设备不仅包括那些要素，而且还包括没有明确列出的其他要素，或者是还包括为这种过程、方法、物品或者设备所固有的要素。在没有更多限制的情况下，由语句“包括一个……”限定的要素，并不排除在包括所述要素的过程、方法、物品或者设备中还存在另外的相同要素。

Claims (10)

  1. 激光扫描显微测量装置，其特征在于：包含激光器(201)、半反半透镜(205)、振镜(206)、扫描物镜(207)、三维位移台(208)和检测模组(210)，激光器(201)的输出光路上布置半反半透镜(205)，半反半透镜(205)的反射光路上依次布置振镜(206)和扫描物镜(207)，透射光路上布置检测模组(210)；激光器(201)发出激光，经过半反半透镜(205)入射到振镜(206)中，振镜(206)控制激光二维偏转，经过扫描物镜(207)后，聚焦于三维位移台(208)上的样品上，激光入射到样品后发生反射，返回扫描物镜(207)和振镜(206)，再经过半反半透镜(205)后进入检测模组(210)。
  2. 根据权利要求1所述的激光扫描显微测量装置，其特征在于：三维位移台(208)包含用于X轴与Y轴二维移动的二维位移台以及连接于其上用于Z轴上下移动的压电陶瓷Z轴单元；压电陶瓷Z轴单元沿Z轴移动样品，在每个Z坐标下，振镜(206)控制激光扫描样品的X-Y面，由检测模组(210)获取不同X-Y-Z坐标下的图像，以单个或多个CCD元件作为虚拟针孔，获取每幅图像中光强最大的虚拟针孔区域的光强，获得不同X-Y-Z坐标下的光强值，得到任意X-Y坐标下最大光强对应的Z坐标，即得到X-Y平面的深度分布，测量出划痕、粗糙度的表面形貌信息。
  3. 根据权利要求1所述的激光扫描显微测量装置，其特征在于：所述激光器(201)安装于激光器安装架(200)上，激光器安装架(200)固定于竖向螺杆(202)上，竖向螺杆(202)上安装在第一转接板(211)上，扩束镜(212)通过转接环安装于第一转接板(211)上，竖向螺杆(202)固定在第二转接板(203)上，第二转接板(203)固定在笼式正交转向板(204)上，笼式正交转向板(204)安装在横向螺杆(213)上，半反半透镜(205)安装在横向螺杆(213)上，横向螺杆(213)的一端与振镜 (206)相旋接，扫描物镜(207)与振镜(206)相旋接，横向螺杆(213)的另一端安装第三转接板(209)，检测模组(210)固定在第三转接板(209)上。
  4. 根据权利要求1或2所述的激光扫描显微测量装置，其特征在于：所述检测模组(210)包含依次设置的用于激光放大的微通道板成像探测器(311)、用于将微通道板成像探测器放大的信号无偏移传送给高帧率面阵相机的光纤光学板(312)以及高帧率面阵相机(301)。
  5. 根据权利要求4所述的激光扫描显微测量装置，其特征在于：高帧率面阵相机(301)固定在相机架(303)上，相机架(303)通过螺杆固定在笼板转接件(302)上，笼板转接件(302)设有用于容纳光纤光学板(312)、微通道板成像探测器(311)、第一卡环(308)、保护镜片(309)、第二卡环(304)的腔室，光纤光学板(312)位于高帧率面阵相机(301)与微通道板成像探测器(311)之间并紧靠，微通道板成像探测器(311)由第一卡环(308)固定，第一卡环(308)前放置有保护镜片(309)，保护镜片(309)由第二卡环(304)固定。
  6. 根据权利要求4或5所述的激光扫描显微测量装置，其特征在于：高帧率面阵相机(301)为MHz帧率的面阵相机，微通道板成像探测器(311)为信号放大10 6～10 7倍的微通道板成像探测器。
  7. 根据权利要求1或3所述的激光扫描显微测量装置，其特征在于：激光器(201)为可输出高斯分布、350～650nm波长的激光器。
  8. 根据权利要求1或3所述的激光扫描显微测量装置，其特征在于：激光器(201)的输出光路上布置扩束镜(212)。
  9. 激光扫描显微测量方法，其特征在于：激光器(201)发出激光，经过半反半透镜(205)入射到振镜(206)中，振镜(206)控制激光二 维偏转，经过扫描物镜(207)后，聚焦于三维位移台(208)上的样品上，激光入射到样品后发生反射，原路返回扫描物镜(207)和振镜(206)，再经过半反半透镜(205)后进入检测模组(210)；
    沿Z轴移动样品，在每个Z坐标下，振镜(206)控制激光扫描样品的X-Y面，由检测模组(210)获取不同X-Y-Z坐标下的图像，以单个或多个CCD元件作为虚拟针孔，获取每幅图像中光强最大的虚拟针孔区域的光强，获得不同X-Y-Z坐标下的光强值，得到任意X-Y坐标下最大光强对应的Z坐标，即得到X-Y平面的深度分布，测量出划痕、粗糙度的表面形貌信息。
  10. 根据权利要求9所述的激光扫描显微测量方法，其特征在于：
    激光器(201)输出高斯分布的激光，经过振镜(206)和扫描物镜(207)后的束腰半径w 0表示为：
    Figure PCTCN2022095230-appb-100001
    式中λ和w 1分别表示波长和扫描物镜前的入射光斑尺寸；瑞利距离z 0＝πw 0 2/λ；距离z处的腰斑半径w z表示如下：
    Figure PCTCN2022095230-appb-100002
    式中z＝-z c表示束腰的坐标位置，坐标z轴沿着激光传播方向，束腰处光斑尺寸w z最小；扫描物镜的焦距为f，采用200mm的像距，像距远大于f，利用高斯成像公式，物距约等于f；物镜的放大倍数为M A＝200/f，检测模组(210)的高帧率面阵相机上的光斑尺寸近似为M Aw z；
    高帧率面阵相机CCD元件尺寸为S，x和y表示相机面上的坐标；只移动z轴，像方测到的功率与物方激光功率成正比，像方总功率为P 0；当物方坐标为z时，峰值光强为I z，入射到相机上的光斑中心的功率P S(z)表示为：
    Figure PCTCN2022095230-appb-100003
    当虚拟针孔尺寸S足够大时，相机上探测到的功率P S(z)始终等于像方总功率P 0，与坐标z无关；当采用单个或多个相机CCD元件时，P S(z)随z轴变化，当束腰处于样品表面时，w z最小，P S(z)最大，探测出该点的高度信息。
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